Showing posts with label Formation: Tiaojishan. Show all posts
Showing posts with label Formation: Tiaojishan. Show all posts

Tuesday, January 16, 2018

[Paleontology • 2018] Caihong juji • A Bony-crested Jurassic Dinosaur with Evidence of Iridescent Plumage highlights Complexity in Early Paravian Evolution


Caihong juji 
Hu, Clarke, Eliason, Qiu, Li, Shawkey, Zhao, D’Alba, Jiang & Xu, 2018

  DOI:   10.1038/s41467-017-02515-y  
Illustration: Velizar Simeonovski

Abstract
The Jurassic Yanliao theropods have offered rare glimpses of the early paravian evolution and particularly of bird origins, but, with the exception of the bizarre scansoriopterygids, they have shown similar skeletal and integumentary morphologies. Here we report a distinctive new Yanliao theropod species bearing prominent lacrimal crests, bony ornaments previously known from more basal theropods. It shows longer arm and leg feathers than Anchiornis and tail feathers with asymmetrical vanes forming a tail surface area even larger than that in Archaeopteryx. Nanostructures, interpreted as melanosomes, are morphologically similar to organized, platelet-shaped organelles that produce bright iridescent colours in extant birds. The new species indicates the presence of bony ornaments, feather colour and flight-related features consistent with proposed rapid character evolution and significant diversity in signalling and locomotor strategies near bird origins.

Caihong juji  prepares to snatch its prey.
Illustration: Zhao Chuang





Fig. 1 Caihong juji holotype specimen (PMoL-B00175).
 Photographs of the slab (a) and counter slab (b) and line drawing (c) of the specimen based on both slabs. Photograph (d) and line drawing (e) of a composite of the rostrum of the skull and mandible exposed on the counter slab and the post-rostrum cranium exposed on the slab. Arrows indicate lacrimal crests. Question mark indicates uncertain identification. Scale bars: 10 cm a–c, 1 cm d and e.

 aof antorbital fenestra, cav caudal vertebra, cev cervical vertebra, dr dorsal rib, dv dorsal vertebra, ect ectopterygoid, emf external mandibular fenestra, en external naris, f feather, fu furcula, ga gastralia, hy hyoid, il ilium, is ischium, la left angular, lar left articular, lc left coracoid, lcr lacrimal crest, ld left dentary, lf left, frontal, lfe left femur, lh left humerus, lj left jugal, ll left lacrimal, lma left maxilla, lm left manus, ln left nasal, lp left pes, lpa left palatine, lpo left postorbital, lq left quadrate, lqj left quadratojugal, lr left radius, ls left scapula, lsp left splenial, lsa left surangular, lsq left squamosal, lt left tibiotarsus, lu left ulna, ma mandible, mf maxillary fenestra, o orbit, p parietal, pm premaxilla, pt pterygoid, pu pubis, rar right articular, rc right coracoid, rd right dentary, rfe right femur, rh right humerus, rm right manus, rp right pes, rpra right prearticular, rq right quadrate, rr right radius, rs right scapula, rt right tibiotarsus, ru right ulna, scl sclerotic bones, sk skull, sy synsacrum

Systematic palaeontology
Theropoda Marsh, 1881
Maniraptora Gauthier, 1986
Paraves Sereno, 1998

Caihong juji gen. et sp. nov.

 Etymology. Caihong is from the Mandarin ‘Caihong’ (rainbow), referring to the beautiful preservation of the holotype specimen of the animal and the array of insights it offers into paravian evolution; juji is from the Mandarin ‘ju’ (big) and ‘ji’ (crest), referring to the animal’s prominent lacrimal crests.

 Holotype. PMoL-B00175 (Paleontological Museum of Liaoning), a nearly complete skeleton with associated plumage preserved on a slab and counter slab from Gangou, Qinglong, northern Hebei Province, Tiaojishan Formation, early Late Jurassic, ~161 Myr.

 Diagnosis. A small theropod with the following autapomorphies within Paraves: accessory fenestra posteroventral to promaxillary fenestra, lacrimal with prominent dorsolaterally oriented crests, robust dentary with anterior tip dorsoventrally deeper than its midsection and short ilium (<50% of the femoral length, compared to considerably >50% in other theropods).

....

An artist's depiction of Caihong juji, a species of theropod dinosaur that lived 160 million years ago in what's now northeastern China.
Illustration: Velizar Simeonovski 


Dongyu Hu, Julia A. Clarke, Chad M. Eliason, Rui Qiu, Quanguo Li, Matthew D. Shawkey, Cuilin Zhao, Liliana D’Alba, Jinkai Jiang and Xing Xu. 2018. A Bony-crested Jurassic Dinosaur with Evidence of Iridescent Plumage highlights Complexity in Early Paravian Evolution. Nature Communications. 9, Article number: 217. DOI:   10.1038/s41467-017-02515-y

New 'Rainbow' Dinosaur May Have Sparkled Like a Hummingbird on.natgeo.com/2DyVWQR via @NatGeo
Little 'Rainbow' Dinosaur Discovered in China  shar.es/1NhEiQ via @LiveScience

  

Friday, August 16, 2013

[PaleoMammalogy • 2013] Rugosodon eurasiaticus • Earliest Evolution of Multituberculate Mammals Revealed by a New Jurassic Fossil from China


Rugosodon eurasiaticus Yuan,  Ji,  Meng,  Tabrum & Luo 2013
lived 160-million years ago on the lakeshores of what is now China

Abstract
Multituberculates were successful herbivorous mammals and were more diverse and numerically abundant than any other mammal groups in Mesozoic ecosystems. The clade also developed diverse locomotor adaptations in the Cretaceous and Paleogene. We report a new fossil skeleton from the Late Jurassic of China that belongs to the basalmost multituberculate family. Dental features of this new Jurassic multituberculate show omnivorous adaptation, and its well-preserved skeleton sheds light on ancestral skeletal features of all multituberculates, especially the highly mobile joints of the ankle, crucial for later evolutionary success of multituberculates in the Cretaceous and Paleogene.

A reconstruction of the extinct rodentlike creature, now called Rugosodon eurasiaticus, which lived 160-million years ago on the lakeshores of what is now China.
 Illustration by April Isch, University of Chicago

'Rugosodon' refers to the rugosity, or wrinkliness, of the mammal's distinctively shaped teeth.

For instance, multituberculates that lived 100 million years or more after R. eurasiaticus and were capable of tree climbing and jumping "had the most interesting ankle bones, capable of 'hyper-back-rotation' of the hind feet." Luo said. "What is surprising about this discovery is that these ankle features were already present in Rugosodon — a land-dwelling mammal."


The fossil of Rugosodon eurasiaticus is preserved in two shale slabs in part (left) and counterpart (right). It is about 6.5 inches (17 cm) long from head to rump, and is estimated to have weighed about 2.8 ounces (80 grams).
 Photographed by Zhe-Xi Luo of University of Chicago and Chongxi Yuan of Chinese Academy of Geological Sciences


Yuan, C.-X., Ji, Q., Meng, Q.-J., Tabrum, A. R. & Luo, Z.-X. 2013. Earliest Evolution of Multituberculate Mammals Revealed by a New Jurassic Fossil. Science. 341, 779–783. 


Fossil reveals features of mammal line that outlived dinosaurs
: Rodent-like animals were deft movers and flexible feeders.

Ancient Rodentlike Creature Once Dominated Earth